<html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script>
    </script>
</head>
<body>
<h1 style="color: green;width:200px;height: 50px" onclick="alert('警告框')"> 警告框</h1>
<h1 style="color: green;width:200px;height: 50px" onclick="confirm('确认框')"> 确认框</h1>
<h1 style="color: green;width:200px;height: 50px" onclick="prompt('提示框')"> 提示框</h1>
</body>
</html>